4電磁理論及磁路

1、WdsExpressionromagismn.電磁，電磁學(xué)electricalapparatus電器，電器設(shè)備motn.電動(dòng)機(jī)generatn.發(fā)電機(jī)fractionaladj.分?jǐn)?shù)的，幾分之一magicfieldn.磁場(chǎng)couplingdevice連接設(shè)備statictransfmer靜態(tài)變壓器electricalpowerdistributioncircuits送變電電路circuitbreakers電路斷路器automaticsw

2、itches自動(dòng)閘relay繼電器quantityn.變量，數(shù)量magicfluxn.磁通量simplifythecomputations估算AmperesCircuitalLaw安培環(huán)路定律hizontalplane水平面righthrule右手（螺旋）法則fluxdensity磁密度teslan.特斯拉，磁通密度的單位permeabilityn.磁導(dǎo)率，磁導(dǎo)系數(shù)henries亨利（電感單位）henriesmeter亨利米（磁導(dǎo)率的單

3、位）absolutepermeability絕對(duì)磁導(dǎo)率relativepermeability相對(duì)磁導(dǎo)率Deltamax克鎳鐵磁性合金ferromagicmaterial鐵磁性材料effectivearean.有效面積nmalcomponentn.法線方向分量webern.韋伯，磁通的單位commonflux共有磁通MagicFieldIntensityH磁場(chǎng)強(qiáng)度electricalmachinery電機(jī)ampereturnsmeter

4、安培圈米Amperescircuitlaw安培回路定律magomotivefce磁勢(shì)magizationcurve磁化曲線demagizationn.退磁residualfluxdensity剩余磁通密度剩磁retentivity記憶力saturation飽和hysteresis磁滯現(xiàn)象hysteresisloop磁滯環(huán)coercivefce矯頑磁力coercivity矯頑力矯頑性magiccircuit磁路maskv.補(bǔ)償cleara

5、ncen.間隙，空隙equivalentcircuit等效電路reluctancen.磁阻examinationn.觀察dimensionn.量綱crosssectionalarea橫截面proptionalto與……成正比inverselyproptionalto與……成反比（4.2）Bisinfactafluxdensityithastheunitsoffluxpersquaremeterteslas.Permeability.It

6、isaacteristicofthesurroundingmediumwhichincreasedecreasethemagicfluxdensityfaspecifiedcurrent.Thepermeabilityofthevacuum(freespace)canbeexpressed70104?????（4.3）Permeabilityisexpressedinunitsofhenrysmeter.Ifthesurrounding

7、mediumisotherthanfreespacetheabsolutepermeabilityisagainreadily?foundfromEq.(4.1).Acomparisonwiththeresultobtainedffreespacethenleadstoaquantitycalledrelativepermeability.Expressedmathematicallywehaver?0????r（4.4）Equatio

8、n(4.4)clearlyindicatesthatrelativepermeabilityissimplyanumericwhichexpressesthedegreetowhichthemagicfluxdensityisincreaseddecreasedoverthatoffreespace.FsomematerialssuchasDeltamaxthevalueofcanexceedonehundredthous.Mostfe

9、rromagicmaterialsr?howeverhavevaluesofinthehundredsofthouss.r?MagicFlux.ItisreasonabletoexpectthatsinceBdenotesmagicfluxdensity?multiplicationbytheeffectiveareathatBperatesshouldyieldthetotalmagicflux.Themagicfluxthrough

10、anysurfaceismerigouslydefinedasthesurfaceintegralofthenmalcomponentofthevectmagicfieldB.Expressedmathematicallywehave??sndAB?（4.5）wheresstsfsurfaceintegralArepresentstheareaofthecoilisthenmalcomponentofBnBtothecoilarea.I

11、thastheunitsofweber.MagicFieldIntensityH.Ofteninmagiccircuitcomputationsitishelpfultowkwithaquantityrepresentingthemagicfieldwhichisindependentofthemediuminwhichthemagicfluxexists.Thisisespeciallytrueinsituationssuchasar